1. Field of the Invention
The device of this invention resides in the area of manhole cover lifters and more particularly relates to an improved manhole cover lifter having means to clean out and gain access into manhole cover rim notches and means to lift and move said manhole cover out of the manhole frame without having to manually lift the manhole cover.
2. Description of the Prior Art
Manhole covers, although particularly well known with regard to sewer systems, are also used in many different types of in-ground installations. To gain access to a manhole in the ground, one must first lift and remove the manhole cover therefrom. Manhole covers are heavy and often can weigh in excess of 180 lbs. The standard practice in the prior art has been to jam a crowbar into a notch located at the rim of the manhole cover, pry the cover up and then manually lift it out. This procedure frequently causes problems in that the manhole cover is extremely heavy and persons lifting out the cover can strain muscles trying to pry it up and lift it out. Moreover, the notch(es) around the cover's perimeter can be filled with tar and other debris which the compaction thereof can prevent easy insertion of the pry bar. Further, the manhole cover, when lifted out, can fall on the worker's hands and feet causing serious injury.
A body of art has developed which includes the following U.S. patents:
U.S. Pat. No. 3,275,299 Meshew PA1 U.S. Pat. No. 3,985,338 Herrmann PA1 U.S. Pat. No. 4,365,925 Girtz PA1 U.S. Pat. No. 4,482,182 Mortensen
Some of the prior art devices disclosed in the above-mentioned patents have means to latch onto holes defined within the manhole cover, either at a side or at a center point thereof and to lock thereon so that the device and cover can be rotated on a pivot member of the device, and the cover lifted out. One problem with some of the above-mentioned prior art is that some manhole covers in current use do not have such holes extending all the way therethrough. Many manhole covers today have a receipt notch in one or more positions around their perimeter, and it is this notch which is felt most practical to address because it is so commonly used. One device that does address the lifting of this type of manhole is disclosed in U.S. Pat. No. 4,482,182 to Mortensen listed above. The device as disclosed has means to latch into opposing notches on each side of the cover by means of a complex mechanism so that such cover can be lifted out by the use of such tool. A problem with prior art tools is that often due to the complexity of the tool and/or tightly sealed-in covers such tools are difficult to use.